Presentation on theme: "Visualisation in mathematics learning: canonical images and semiosis Tracy Wylie and Laurinda Brown Kingsfield School, South Gloucestershire and University."— Presentation transcript:
Visualisation in mathematics learning: canonical images and semiosis Tracy Wylie and Laurinda Brown Kingsfield School, South Gloucestershire and University of Bristol, GSoE, UK
What is a canonical image? An image that is economical (Breen, 1997, PME 21) in that it gives direct access to the mathematical concept. What does this mean? Why might a teacher and researcher be interested in studying them?
PME32 Proceedings Trigonometry has been discussed in short orals and a plenary: Plenary, Patrick Thompson, Vol 1 pp Focusing on misconceptions, SOs, Vol 1, p. 264 and p. 267 What is a canonical image for trigonometry?
The trig image
How would you do these? Students were asked to write down the value of (1/2 + √3/2) 5 Students were asked to find the general solution to the equation cos (2x + π/6) = 1/√2
What happened? Hand gesture - Student F appears to be mimicking the shape of the cosine function. His pen is moving back and forth over the crest of the graph. It goes like that [gestures with hand] so it’s gonna be… no you’re gonna have to get the other one is 0 minus whatever the first one is because of the graph [draws on own sheet] ‘cause the graph will be like that and that point there is say π by 3, for instance, and that’s going to be minus…
Where next? I began this piece of research with a canonical image for trigonometry. I would now suggest that an image is canonical if it can allow an individual working on mathematics to have the flexibility to use the image directly in a number of ways with a variety of problems.